Khan.scratchpad.disable(); For every level Tiffany completes in her favorite game, she earns $660$ points. Tiffany already has $280$ points in the game and wants to end up with at least $3470$ points before she goes to bed. What is the minimum number of complete levels that Tiffany needs to complete to reach her goal?
Answer: To solve this, let's set up an expression to show how many points Tiffany will have after each level. Number of points $=$ $ $ Levels completed $\times$ Points per level $+$ Starting points Since Tiffany wants to have at least $3470$ points before going to bed, we can set up an inequality. Number of points $\geq 3470$ Levels completed $\times$ Points per level $+$ Starting points $\geq 3470$ We are solving for the number of levels to be completed, so let the number of levels be represented by the variable $x$ We can now plug in: $x \cdot 660 + 280 \geq 3470$ $ x \cdot 660 \geq 3470 - 280 $ $ x \cdot 660 \geq 3190 $ $x \geq \dfrac{3190}{660} \approx 4.83$ Since Tiffany won't get points unless she completes the entire level, we round $4.83$ up to $5$ Tiffany must complete at least 5 levels.